<!DOCTYPE html><html lang="zh-Hans"><head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1"><meta name="description" content="iOS代码执行时间"><meta name="keywords" content=""><meta name="author" content="kyren"><meta name="copyright" content="kyren"><title>iOS代码执行时间 | Kyren's Blog</title><link rel="shortcut icon" href="/melody-favicon.ico"><link rel="stylesheet" href="/css/index.css?version=1.9.0"><link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/font-awesome@latest/css/font-awesome.min.css?version=1.9.0"><meta name="format-detection" content="telephone=no"><meta http-equiv="x-dns-prefetch-control" content="on"><link rel="dns-prefetch" href="https://cdn.jsdelivr.net"><link rel="dns-prefetch" href="https://hm.baidu.com"><script>var _hmt = _hmt || [];
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<p>StackOverflow <a target="_blank" rel="noopener" href="https://stackoverflow.com/questions/2129794/how-to-log-a-methods-execution-time-exactly-in-milliseconds">How to log a method’s execution time exactly in milliseconds?</a></p>
<figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">//单位换算</span></span><br><span class="line"><span class="number">1</span>分(min)=<span class="number">60</span>秒(s)</span><br><span class="line"><span class="number">1</span>秒(s)=<span class="number">1000</span>毫秒(ms)</span><br><span class="line"><span class="number">1</span>毫秒(ms)=<span class="number">1000</span>微秒(μs)</span><br><span class="line"><span class="number">1</span>微秒(μs)=<span class="number">1000</span>纳秒(ns)</span><br></pre></td></tr></table></figure>



<p>一、CFAbsoluteTime （纳秒级的精确度 ）</p>
<figure class="highlight objectivec"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="built_in">CFAbsoluteTime</span> startTime =<span class="built_in">CFAbsoluteTimeGetCurrent</span>();</span><br><span class="line"><span class="comment">//在这写入要计算时间的代码</span></span><br><span class="line">...</span><br><span class="line"><span class="built_in">CFAbsoluteTime</span> executionTime = (<span class="built_in">CFAbsoluteTimeGetCurrent</span>() - startTime);</span><br><span class="line"><span class="built_in">NSLog</span>(<span class="string">@&quot;executionTime %f ms&quot;</span>, executionTime *<span class="number">1000.0</span>);</span><br><span class="line"><span class="comment">//打印出来代码执行时间 单位ms(executionTime 7.062972 ms)</span></span><br></pre></td></tr></table></figure>



<p>block方式</p>
<figure class="highlight plaintext"><figcaption><span>c</span></figcaption><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br></pre></td><td class="code"><pre><span class="line">TIME_BLOCK(^&#123;</span><br><span class="line">    //执行需要测试的代码</span><br><span class="line">&#125;);</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">CGFloat TIME_BLOCK(void (^block)(void))&#123;</span><br><span class="line">    NSTimeInterval startTime = CACurrentMediaTime();</span><br><span class="line">    block ();</span><br><span class="line">    CFTimeInterval elapsedTime = CACurrentMediaTime() - startTime;</span><br><span class="line">    NSLog(@&quot;executionTime = %f ms&quot;,  elapsedTime *1000.0);</span><br><span class="line">    return (CGFloat)elapsedTime / NSEC_PER_SEC;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">//key 标识符</span><br><span class="line">CGFloat TIME_BLOCKWithkey (NSString *key,void (^block)(void)) &#123;</span><br><span class="line">    NSTimeInterval startTime = CACurrentMediaTime();</span><br><span class="line">    block ();</span><br><span class="line">    CFTimeInterval elapsedTime = CACurrentMediaTime() - startTime;</span><br><span class="line">    NSLog(@&quot;%@ executionTime = %f ms&quot;,key,elapsedTime *1000.0);</span><br><span class="line">    return (CGFloat)elapsedTime / NSEC_PER_SEC;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>

<p>二、NSDate</p>
<figure class="highlight plaintext"><figcaption><span>c</span></figcaption><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">NSDate *methodStart = [NSDate date];</span><br><span class="line">/* ... Do whatever you need to do ... */</span><br><span class="line">NSDate *methodFinish = [NSDate date];</span><br><span class="line">NSTimeInterval executionTime = [methodFinish timeIntervalSinceDate:methodStart];</span><br><span class="line">NSLog(@&quot;executionTime = %f ms&quot;,  executionTime *1000.0);</span><br><span class="line">//打印出来为代码执行时间 单位ms(7.090032 ms)</span><br></pre></td></tr></table></figure>

<p>简写宏</p>
<figure class="highlight objectivec"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line">宏定义</span><br><span class="line"><span class="meta">#<span class="keyword">define</span> TICK   NSDate *startTime = [NSDate date]</span></span><br><span class="line"><span class="meta">#<span class="keyword">define</span> TOCK   NSLog(@<span class="string">&quot;Time: %f&quot;</span>, -[startTime timeIntervalSinceNow])</span></span><br><span class="line"></span><br><span class="line">TICK</span><br><span class="line"><span class="comment">/* ... Do Some Work Here ... */</span></span><br><span class="line">TOCK</span><br></pre></td></tr></table></figure>



<p>三、<code>CACurrentMediaTime()</code>返回的精度-微秒级别</p>
<p> CACurrentMediaTime方法获取到的时间，是手机从开机一直到当前所经过的秒数。</p>
<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">NSTimeInterval startTime = CACurrentMediaTime();</span><br><span class="line"></span><br><span class="line">// your code goes here</span><br><span class="line">CFTimeInterval elapsedTime = CACurrentMediaTime() - startTime;</span><br><span class="line">NSLog(@&quot;executionTime = %f ms&quot;,  elapsedTime *1000.0);</span><br><span class="line">//打印出来为代码执行时间 单位ms(7.299827 ms)</span><br></pre></td></tr></table></figure>

<ul>
<li>NSDate 属于Foundation</li>
<li>CFAbsoluteTimeGetCurrent() 属于 CoreFoundatio</li>
<li>CACurrentMediaTime() 属于 QuartzCore</li>
</ul>
<p>第二种：（将运行代码放入下面的Block中，返回时间）</p>
<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br></pre></td><td class="code"><pre><span class="line">#import &lt;mach/mach.h&gt;</span><br><span class="line">#import &lt;mach/mach_time.h&gt;  // for mach_absolute_time() and friends</span><br><span class="line"></span><br><span class="line">CGFloat TIME_BLOCK (void (^block)(void)) &#123;</span><br><span class="line">    mach_timebase_info_data_t info;</span><br><span class="line">    if (mach_timebase_info(&amp;info) != KERN_SUCCESS) return -1.0;</span><br><span class="line"></span><br><span class="line">    uint64_t start = mach_absolute_time ();</span><br><span class="line">    block ();</span><br><span class="line">    uint64_t end = mach_absolute_time ();</span><br><span class="line">    uint64_t elapsed = end - start;</span><br><span class="line"></span><br><span class="line">    uint64_t nanos = elapsed * info.numer / info.denom;</span><br><span class="line">    return (CGFloat)nanos / NSEC_PER_SEC;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line">//加入key</span><br><span class="line">CGFloat TIMEKey_BLOCK(NSString *key, void (^block)(void)) &#123;</span><br><span class="line">    mach_timebase_info_data_t info;</span><br><span class="line">    if (mach_timebase_info(&amp;info) != KERN_SUCCESS)</span><br><span class="line">    &#123;</span><br><span class="line">        return -1.0;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    uint64_t start = mach_absolute_time();</span><br><span class="line">    block();</span><br><span class="line">    uint64_t end = mach_absolute_time();</span><br><span class="line">    uint64_t elapsed = end - start;</span><br><span class="line"></span><br><span class="line">    uint64_t nanos = elapsed * info.numer / info.denom;</span><br><span class="line">    float cost = (float)nanos / NSEC_PER_SEC;</span><br><span class="line"></span><br><span class="line">    NSLog(@&quot;key: %@ (%f ms)\n&quot;, key, cost * 1000);</span><br><span class="line">    return cost;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">uint64_t getTickCount(void)</span><br><span class="line">&#123;</span><br><span class="line">    static mach_timebase_info_data_t sTimebaseInfo;</span><br><span class="line">    uint64_t machTime = mach_absolute_time();</span><br><span class="line"></span><br><span class="line">    // Convert to nanoseconds - if this is the first time we&#x27;ve run, get the timebase.</span><br><span class="line">    if (sTimebaseInfo.denom == 0 )</span><br><span class="line">    &#123;</span><br><span class="line">        (void) mach_timebase_info(&amp;sTimebaseInfo);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    // Convert the mach time to milliseconds</span><br><span class="line">    uint64_t millis = ((machTime / 1000000) * sTimebaseInfo.numer) / sTimebaseInfo.denom;</span><br><span class="line">    return millis;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>





<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line">/**</span><br><span class="line"> * 计算脚本时间</span><br><span class="line"> * @param $last 最后一次的运行clock</span><br><span class="line"> * @param $key  标识</span><br><span class="line"> * @return 当前clock</span><br><span class="line"> */</span><br><span class="line">double timeNow(double last, char* key)&#123;</span><br><span class="line">    clock_t now = clock();</span><br><span class="line">    printf(&quot;time:%fs \t key:%s \n&quot;, (last != 0) ? (double)(now - last) / CLOCKS_PER_SEC : 0, key);</span><br><span class="line">    return now;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line">double t1 = t(0, &quot;&quot;);</span><br><span class="line">//do something</span><br><span class="line">t(t1, &quot;end&quot;);</span><br></pre></td></tr></table></figure>

<p>参考：</p>
<p><a target="_blank" rel="noopener" href="https://zhuanlan.zhihu.com/p/24377367?refer=mrpeak">iOS关于时间的处理</a></p>
</div></article><div class="post-copyright"><div class="post-copyright__author"><span class="post-copyright-meta">文章作者: </span><span class="post-copyright-info"><a href="mailto:undefined">kyren</a></span></div><div class="post-copyright__type"><span class="post-copyright-meta">文章链接: </span><span class="post-copyright-info"><a href="http://huluo666.gitee.io/2017/12/27/iOS代码执行时间/">http://huluo666.gitee.io/2017/12/27/iOS代码执行时间/</a></span></div><div class="post-copyright__notice"><span class="post-copyright-meta">版权声明: </span><span class="post-copyright-info">本博客所有文章除特别声明外，均采用 <a target="_blank" rel="noopener" href="https://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA 4.0</a> 许可协议。转载请注明来自 <a href="http://huluo666.gitee.io">Kyren's Blog</a>！</span></div></div><div class="post-meta__tag-list"></div><nav id="pagination"><div class="prev-post pull-left"><a href="/2017/12/27/JSON%E6%95%B0%E6%8D%AE%E5%8E%8B%E7%BC%A9/"><i class="fa fa-chevron-left">  </i><span>JSON数据压缩</span></a></div><div class="next-post pull-right"><a href="/2017/12/25/iOS%E5%8F%82%E8%80%83%E5%8A%A8%E7%94%BB/"><span>iOS参考动画</span><i class="fa fa-chevron-right"></i></a></div></nav></div></div><footer><div class="layout" id="footer"><div class="copyright">&copy;2022 By kyren</div><div class="framework-info"><span>驱动 - </span><a target="_blank" rel="noopener" href="http://hexo.io"><span>Hexo</span></a><span class="footer-separator">|</span><span>主题 - </span><a target="_blank" rel="noopener" href="https://github.com/Molunerfinn/hexo-theme-melody"><span>Melody</span></a></div><div class="footer_custom_text">hitokoto</div><div class="busuanzi"><script async src="//busuanzi.ibruce.info/busuanzi/2.3/busuanzi.pure.mini.js"></script><span id="busuanzi_container_page_pv"><i class="fa fa-file"></i><span id="busuanzi_value_page_pv"></span><span></span></span></div></div></footer><i class="fa fa-arrow-up" id="go-up" aria-hidden="true"></i><script src="https://cdn.jsdelivr.net/npm/animejs@latest/lib/anime.min.js"></script><script src="https://cdn.jsdelivr.net/npm/jquery@latest/dist/jquery.min.js"></script><script src="https://cdn.jsdelivr.net/npm/@fancyapps/fancybox@latest/dist/jquery.fancybox.min.js"></script><script src="https://cdn.jsdelivr.net/npm/velocity-animate@latest/velocity.min.js"></script><script src="https://cdn.jsdelivr.net/npm/velocity-ui-pack@latest/velocity.ui.min.js"></script><script src="/js/utils.js?version=1.9.0"></script><script src="/js/fancybox.js?version=1.9.0"></script><script src="/js/sidebar.js?version=1.9.0"></script><script src="/js/copy.js?version=1.9.0"></script><script src="/js/fireworks.js?version=1.9.0"></script><script src="/js/transition.js?version=1.9.0"></script><script src="/js/scroll.js?version=1.9.0"></script><script src="/js/head.js?version=1.9.0"></script><script src="/js/search/local-search.js"></script><script>if(/Android|webOS|iPhone|iPod|iPad|BlackBerry/i.test(navigator.userAgent)) {
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